The interface strength of low-dimensional nano-components such as films and islands formed on substrates has been investigated in this project, and the focus is put on the mechanics of crack initiation from the free interface edge and propagation along the interface. The series of experiments elucidates the applicability of fracture mechanics concept on the structures. We proposed experimental methods for evaluating the initiation strength of an interface crack in submicron films and islands deposited on substrates. The initiation is governed by the singular stress field, and the criterion is prescribed by the stress intensity parameter. Using special loading apparatus built in a TEM, we developed a crack initiation method for nano-components and the role of plasticity on the delamination is clarified. Subcritical crack growth along an interface between submicron films under fatigue was also investigated by modified four-point bend method.